The invention relates to a toothbrush having a head part, a carrier element and a plurality of cutouts, and to a process which is intended for producing such a toothbrush that includes guiding the bristle filaments through the cutouts and connecting the carrier element to the head part. The invention also relates to a head part for a changeable-head toothbrush. The present application claims priority to German Application No. 102 59 723.5 filed Dec. 19, 2002.
Producing toothbrushes by AFT (Anchor Free Tufting) technology has great advantages in relation to the conventional bristle-covering operation, in which bristle filaments bent around anchors or clips are stuffed into the head part of the brush. Because the shape of the clusters of bristles is not predetermined by the size of the corresponding fastening means, more or less any desired bristle arrangements can be realized by means of AFT. In the case of AFT, use is made of a carrier plate with a plurality of cutouts through which clusters of bristle filaments are guided. The rear ends are then melted for permanent connection to the carrier plate. AFT technology is described, for example, in EP-A 0 972 464, EP-A 0 405 204 or EP-A 0 567 672. The bristle covered carrier plate is then connected to the head part of the toothbrush. Ultrasonic welding, which is described for example in DE-U 2000 6311, is preferred.
AFT technology straightforwardly allows the production of different bristle profiles, by the bristle filaments, which are guided loosely through the cutouts, being forced into the desired profile shape, using a template, before the incipient melting. However, the properties of a toothbrush or of its bristle arrangement, such as rigidity, wear and cleaning efficiency, are determined not just by the material selection and the profile shape, but also by the length and the setting angle of the bristles. Up until now, it was not possible for these parameters, in particular the bristle length and profile shape, to be varied independently of one another in order to optimize the cleaning properties further.
WO 94/22346 discloses a toothbrush with an inflection in the bristle-carrying head part, but does not describe the production process. The conventional bristle-covering operation of such a brush involves high outlay because it is only possible to compensate for height differences in the head part by compensating movements of the stopping tool.